Wrong serialization order of Array.from() result

[gaearon]

Serializer test:

function fn(arg) {
  if (!arg.condition) {
    return null;
  }

  var fooArr = Array.from(arg.foo);
  return arg.calculate(function() {
    return fooArr;
  });
}

if (global.__optimize) __optimize(fn);

inspect = function() {
  return JSON.stringify([
    fn({condition: false}),
    fn({
      condition: true,
      foo: 10,
      calculate(f) { return f().length; }
    }),
    fn({
      condition: true,
      foo: [1, 2, 3],
      calculate(f) { return f().length; }
    }),
  ])
}

Output:

var fn;
(function () {
  var _$5 = this;

  var _$6 = _$5.Object;
  var _$7 = _$6.assign;
  var _$8 = _$5.Array;
  var _$9 = _$8.from;

  var _1 = function (arg) {
    var _B = function () {
      return _C;
    };

    var _$0 = _$7(arg).condition;

    var _4 = !_$0;

    var _C = _4 ? void 0 : _$2; // <--------- _$2 is used before definition

    if (!_4) {
      var _$1 = _$7(arg).foo;

      var _$2 = _$9(_$1); // <---------- _$2 is defined

      var _$3 = _$7(arg).calculate;

      var _$4 = arg.calculate(_B);
    }

    return _4 ? null : _$4;
  };

  var _0 = function () {
    return JSON.stringify([fn({
      condition: false
    }), fn({
      condition: true,
      foo: 10,

      calculate(f) {
        return f().length;
      }

    }), fn({
      condition: true,
      foo: [1, 2, 3],

      calculate(f) {
        return f().length;
      }

    })]);
  };

  _$5.fn = _1;
  inspect = _0;
}).call(this);

This seems similar to #1924 but #1926 does not fix it. So I filed a separate issue.

[gaearon]

The Array.from-specific part has been fixed in #1970.
The remaining issue is tracked as #1973 (and might be "by design").